Loss of Pressure (softwash)

I have a 100psi pump with1/2in 300ft hose for my soft wash system. Normally it works great but today was the first time I used it on a 2 story house and it kept loosing pressure. I checked the line for kinks and the pump to see if it was clear of debris, my guess was it was due to the height.

Is this accurate or am I missing something?

Check for leaks on the suction side of the pump. They’re hard to detect, but will definitely mess with your output. Sometimes hose clamps will work themselves loose over time.